Ken Batt from the Bureau of Meteorology speaks to the media about the coming changes in weather patterns around Canberra at ESA Headquarters on Tuesday.

Ken Batt from the Bureau of Meteorology speaks to the media about the coming changes in weather patterns around Canberra at ESA Headquarters on Tuesday. Photo: Jeffrey Chan

Canberrans got some respite from sweltering heat thanks to a cool change, but the mercury is set to soar once again at the weekend.

And authorities are bracing for a possible repeat of Tuesday's severe fire conditions on Saturday. A total fire ban remains in place across the region.

The forecast came on a day the weather threw almost everything short of snow at Canberrans.

Heat of the moments

It started with the promise of blistering heat - a 38 degree day - heat-related hospitalisations and an extreme fire danger warning.

It ended with powerful winds bringing down trees, dust haze, reports of weak lightning around Uriarra and isolated spots of rain. Wednesday should bring a degree of solace for firefighters and Canberrans after a day on edge, with the mercury set to reach just 29 degrees.

But a total fire ban will still be in place across the ACT, with a very high fire danger level expected.

''Without the winds, without the strength of the winds, and slightly lower daytime temperatures … the fire risk does drop away so we're looking at high to very high [fire danger],'' the Bureau of Meteorology's Ken Batt said.

''It's not a weather-induced fire ban, it's more to help NSW and the area around the ACT.''

The bureau and the ACT Emergency Services Agency is bracing for more volatile conditions on Saturday, when the mercury is set to reach 37 degrees after a gradual build-up over several days. ''The winds at this stage aren't looking as strong as they have been today [Tuesday] but there's the chance,'' Mr Batt said.

Tuesday's temperature soared above 30 degrees by 9.30am and continued to climb, reaching 38 degrees at Canberra Airport at 4.08pm before dropping again.

It was expected to slip further overnight, with a minimum of 14 degrees tipped for Wednesday.

Winds reached speeds of up to 83km/h at 1.20pm before dying down in the evening.

The powerful gusts caused devastation in the suburbs, with emergency services receiving 122 calls relating to fallen trees or branches by the early evening. Paramedics treated 19 people for heat-related injuries, including a 90-year-old.

The Emergency Services Agency urged Canberrans to drink plenty of water. ''Most importantly, don't forget your elderly and frail relatives and neighbours and pay special attention to the health needs of babies and young children who can be adversely affected by the heat,'' it said.